Though petroleum energy has a contributed greatly to the development of human society, there are currently many problems associated with its use, including diminishing reserves, unequal distribution of resources, environmental pollution, and the like, thus active research has been conducted toward biomass as an entire/partial substitute for petroleum resources.
“Biomass” is, in a broad sense, intended to encompass all materials derived from biological origin. In a narrow sense, it refers to plants or plant-based materials such as corns, beans, linseeds, sugarcanes, palm oil, and so on, but its meaning may be generally expanded to living organisms, and metabolites partly responsible for carbon cycles.
Since the 1970s, preparation of high value-added materials from biomass has been under active study, but no independent models with commercial applicability have yet been suggested. The reasons may be found in some disadvantages of biomass as follows: First, the product from biomass is quantitatively limited. Petroleum resources, although locally distributed over the world, are yet quantitatively sufficient to meet the world's energy and chemical demands. In contrast, biomass, although omnipresent compared to petroleum resources, requires additional processes for the production thereof as useful materials. Hence, biomass is far inferior to petroleum resources in terms of output. Second, biomass is poor in cost competitiveness. Since biomass is produced fundamentally on the basis of consumption, it is difficult to find surplus biomass of low price as a feed for substituting for petroleum resources. Third, biomass is difficult to secure in a sufficient amount. For petroleum resources, the problem of creation does not exist because they are naturally occurring in particular regions and are produced in mining lots. On the other hand, since biomass fundamentally requires a large cultivation area for the production thereof, it is difficult to secure a large quantity of biomass for use as resources. Finally, since biomass-based products have been limited to alternatives to low-price materials such as gasoline or diesel, it is difficult to suggest models that can be independently commercialized without policy support.
In recent years, however, biomass production techniques have been improved to overcome the above-mentioned problems. Particularly as for CPO (Crude Palm Oil) and SBO (Soybean Oil) suggested as surplus biomass, their worldwide production amounts to as much as ones of million tons, and they can be bought in an amount of one million tons or more from the open market. In addition, with the increased production of the biomass products year by year, they have exhibited low price volatility and can be purchased from the open market. Further, CPO has attracted intensive attention as an alternative material to petroleum-based products since it can be obtained on a mass scale and its price is stabilized in the open market. CPO consist of 90 to 95% of triglycerides, a ratio of C16:C18 carbon chains, which mainly compose the triglycerides, is about 45:55 (by weight basis). The remainder except the triglycerides, that is, 5 to 10% by weight of COP is covered mainly by C16 and/or C18 fatty acids with a mono- or diglyceride content of approximately 10%. The triglyceride selectively isolated from refined CPO is called RBD (Refined Bleached Deodorized) palm oil while the removed fatty acids and mono- or diglycerides, amounting to 5˜10% by weight, are called PFAD (Palm Fatty Acid Distillate). The amount currently obtained in the open market approximates 1,000,000 tons for CPO and 400,000 tons for PFAD. The RBD triglyceride, and illustrative fatty acids constituent of PFAD are depicted in FIG. 1. Carbon chains constituent of CPO and PFAD are listed in Table 1, below.
TABLE 1CPO1PFAD2Fatty Acid(wt %)(wt %)14:0 Myristic0.5 to 5.90.9 to 1.516:0 Palmitic32 to 5943 to 5116:1 Palmitoleic<0.6—18:0 Stearic1.5 to 8.04 to 518:1 Oleic27 to 5233 to 4018:2 Linoleic5.0 to 14  9 to 1118:3 Linolenic<1.50.2 to 0.620:0 Eicosanoic<1.0—1composed mainly of triglycerides2composed mainly of fatty acids
Meanwhile, models for commercially producing high value-added products, such as lubricant base oils, other than fuels, from biomass have recently suggested. For example, Group BI lubricant base oils were produced from a material containing unsaturated compounds at a content of 50% by weight or higher by oligomerization, deoxygenation, and isodewaxing (IDW) (e.g., U.S. Pat. Nos. 7,459,597 and 7,888,542, etc.). The reactions described above aim for the polymerization of olefins present within biomass, and thus require that the material have an olefinic content of 50% or higher so as to increase activity. Since the polymerization is a random polymerization, it results in producing naphthenic lubricant base oils with a naphthenic content of about 72%. Particularly, isodewaxing is conducted to improve the lubricant base oils in fluidity. On the other hand, the technique for production of lubricant base oils from fatty acids was proposed through pre-hydrotreatment, ketonization, hydrodeoxygenation (HDO), and IDW (for example, U.S. Pat. No. 8,048,290). These processes are described to produce the product (Group III base oil) at a yield of 36% of the feed (fatty acids).
In addition, a process for producing 1-decene, used as a raw material of PAO (poly alpha-olefin), and ester lubricant base oils corresponding to class Group V from triglycerides is known (U. S. Patent Application No. 2012/0115762). The method consists of metathesis, oligomerization, and hydroisomerization. For economical profits, it is important to control the content of C18:1 to a high level in the technique. Further, it is necessary to prevent the structure collapse of ester and the inactivation of precious metal catalysts during a hydrogenation for the skeletal isomerization of esters